Initially, the "High Power" pistol was designed by John M. Browning in 1925 and was patented in the USA in 1927, soon after the death of the Browning. The design was aquired by Belgian state-owned company FN Herstal, and improved by FN designer Dieudonne Saive. The resulting pistol was shelved until 1935, when Belgian army was ready to adopt new sidearm. The HP was offered for trials and won, and was adopted as a Model 1935 pistol. Soon after that it was also adopted by Belgian police and by many foreign countries, including Britich Commonwealth ones (UK, Canada, Australia etc.). The High Power is the only sidearm that served for both sides in WW2 - Germany used many HPs manufactured in occupied Belgium, while Allies used HPs manufactured mostly in Canada by company Inglis. The HP continues its service well into XXI century with belgian Army and Police, British army and many other military and Law Enforcement agencies, being second longest living service pistols after the another famous Browning`s design, the Colt 1911.
Thechnically, the High Power pistol, also known as Browning HP 35, GP 35 or Model 1935, is a recoil operated, locked breech pistol. It uses linkless barrel to slide locking (see picture above), invented by Browning. The trigger is single action, with external hammer. Original HPs featured frame mounted safety at the left side of the frame, that locks both sear and slide. Modern versions, since Mark II, also featured ambidextrous safety levers, that are also more comfortable to operate. Original HPs were available with two sight wersions - with standart fixed sights, and with rear tangent sights ajustable for distance from 50 to 500 meters. Some pre- and WW2-time guns also featured backstraps with cuts to accomodate removable shoulder stocks/holsters. Grip panels were made from wood, and pistols were availabli with or without lanyard rings. The HP was the first military pistol to have high capacity, staggered column magazine for 13 rounds plus one loaded in the chamber.
Newer Military/LE versions, such as Mk.II and recent Mk.III (also marketed under the name of HP-SA with added firing pin safety), featured more modern fixed combat sights and polymer grip panels. Commercial models may feature different sight options and finiches. Lates addition to the High Power family is a variation chambered in .40S&W cartridge. It has redesigned and strenghtened slide to accomodate more powerful cartridge, and magazine capacity of 10 rounds.
In 1980`s or so FN also developed version of the HP with double action trigger, that was named HP-DA. It is still marketed by FN, but didn`t catch the market as well as its predescessor did.
Copies and clones of the HP are still manufactured around the worls, such as Hungarian FEG 9, Bulgarian Arcus etc.
9mm Parabellum (also 7.65mm Parabellum and .40S&W in commercial/civilian models)
13 rounds (10 rounds in .40SW)